[Elvis]

http://fivethirtyeight.com/datalab/dear ... e-stopped/

Dear NFL: Kickers Will Not Be Stopped

By BENJAMIN MORRIS

Did you hear about the NFL’s incredible new rule? On a point-after try, a defense will be able to score a 1-point safety by stopping the attempting team in its own end zone. Oh, and the new rule also moved the line of scrimmage for an extra point to the 15-yard line, making it the equivalent of a 33-yard field goal attempt.

But indulge me for two seconds and let’s talk about this 1-point safety, a totally new thing in the NFL. Sure, it’s something that probably won’t come up very often – or, you know, ever. This new safety would occur if the offensive team fumbled the ball backwards, then the players kept knocking it backwards because of their gigantic butter-fingers until an offensive player finally recovered it in his own end zone (yes, on the other end of the field), where they were immediately tackled. (The offense can also score a 1-point safety, but that’s boring.) This opens up the tantalizing possibility of game scores traditionally reserved for baseball, soccer, or curling, like 6-1 (if the only points scored are a touchdown and a defensive point after safety) or 10-1 (if the only points scored are a touchdown, a defensive point-after safety, and two regular safeties).

OK, thanks. Back to the longer extra point: The theory is that the league wants to make the play more exciting by making it less “automatic,” and perhaps by encouraging teams to go for two points more often. They’re unlikely to be very successful on either count.

Kickers now convert extra points more than 99 percent of the time. That will almost certainly drop, but not by very much. It has been bandied about that kickers have made “only” 91.6 percent of attempts from this distance in the last 10 years. But 10 years is an eternity for kickers – they’re a whole lot better now than they were in 2005. As noted by Kevin Seifert, kickers have made 94.4 percent of field goals from this new distance over the last three years, and 96.7 percent last year. And that doesn’t account for the point-after kicks being slightly easier than their field goal counterparts: They’re never rushed for time, and they’re always taken from the center of the field (technically from wherever the kicker prefers). According to Pro Football Focus, kickers have made 97.6 percent of attempts taken from 30-35 yards from the dead-center of the field over the past three years.

When I wrote about kickers in January I developed an era-sensitive model for kickers that at least partially accounts for hash marks (and, if I may, is scary accurate). It’s slightly more conservative than that Pro Football Focus mark, but predicts that kickers would make 96.4 percent of 33-yard kicks next year, rising to about 98 percent over the next 10 years.

This isn’t the first time the NFL has been uncomfortable with how good kickers have gotten at their jobs. In 1974, the league moved the goal posts to the back of the end zone, effectively making XPs and other kicks 10 yards harder. Extra point success dropped from 98 percent the year before to 92.1 percent the year after. But it didn’t take long for kickers to recover:

From an excitement standpoint, it’s tough to see a significant difference between teams making their extra points 96-98 percent of the time rather than 99. Even if misses happen slightly more often, they’re still going to be infrequent enough that I’d guess they’re more likely to annoy fans after the fact than keep them in suspense beforehand.

And while this should marginally improve the math in favor of 2-point attempts, it’s not nearly dramatic enough to make going for two points the obviously better option. (It would have been if the NFL had also moved the line of scrimmage on 2-point attempts up to the 1-yard line, per the Eagles proposal.) Defenses will also be able to score two points on the play by returning a fumble, interception or blocked kick for a “touchdown,” as is the rule in college.

And coaches are already pretty irrational about going for two. They have been converted about 47.4 percent of the time over the past 10 years, which would be enough to make them roughly the equivalent of kicking extra points (from an expected-value perspective; though that number may be low because teams that make 2-point attempts tend to be slightly worse than average). At the very least, the expected value of going for it versus kicking is so close that the decision should be dominated by the tactical situation (such as how far ahead or behind they are, and whether they should be playing it safe or trying to gamble) and how good the teams are in short yardage situations. But coaches still basically only make the 2-point attempt when they’re required to.

If there is a big shift in favor of going for two, I think it’s more likely to be a result of coaches deciding the new rule gives them cover for it, rather than a large and fundamental shift in the math. And there’s precedent for this: The all-time high for successful 2-point attempts made was 59, set in 1994 – the year the play was first introduced.

[Hacksaw]

The 2 yard extra point was a bit too easy but they now lose the element of surprise on fake conversions. Line up for a kick and Hekker hits the TE who leaked through kind of play.

[Elvis]

The 2 yard extra point was a bit too easy but they now lose the element of surprise on fake conversions. Line up for a kick and Hekker hits the TE who leaked through kind of play.

I like that you can return a blown try for points now but yeah, don't like having the one and two point conversions from different spots.

Do we know what happens if someone does run a fake from the 15, or scores on a botched snap? Is it one or two points?

[Hacksaw]

The 2 yard extra point was a bit too easy but they now lose the element of surprise on fake conversions. Line up for a kick and Hekker hits the TE who leaked through kind of play.

I like that you can return a blown try for points now but yeah, don't like having the one and two point conversions from different spots.

Do we know what happens if someone does run a fake from the 15, or scores on a botched snap? Is it one or two points?

Not certain but you'd have think that a kick is 1 point and a pass or run would be 2,, even if on a broken play.

The potential for block returns just went up. So did it say you get 2 for a block FG-runback? Is that only if a FG is blocked? Can you advance a fumble on a 2 point attempt?

There is also the chance that a coach like Fisher might attempt a fake FG from the 15 which would mean that an extra player will have to drop back..

[Elvis]

http://www.baltimoresun.com/sports/rave ... story.html

Ravens guard, math scholar John Urschel analyzes extra-point rule change.

As a math scholar, Ravens offensive guard John Urschel is accustomed to applying his knowledge and authoring complicated papers in academic journals.

A winner of the William V. Campbell Trophy given to the top scholar-athlete in the equivalent of the academic Heisman Trophy, Urschel has taught Vector Calculus Trigonometry to Penn State students.

And the 4.0 grade point average student had a paper published this year in the Journal of Computational Mathemetatics called “A Cascadic Multigrid Algorithm for Computing the Fiedler Vector of Graph Laplacians.” A year ago, Urschel published a paper in the top math journal, Linear Algebra and Its Applications called “Spectra Bisection of Graphs and Connectedness.”

So, Urschel's analysis of the NFL moving back its extra-point to the 15-yard line is worth a perusal. Urschel, whose Twitter handle is @MathMeetsFBall, wrote a piece on The Players Tribune, where he's the advanced stats columnist, called "Math Meets Football: Is the New Extra Point a Game-Changer?"

With kickers making 99.5 percent of their extra points last season and missing just two field goals from 33 yards, many have predicted that the statistics won't change dramatically on extra points this season with the rule change.

Urschel predicted that extra points will fall to roughly a 92.8 percent success rate this season. And he posited that attempting the two-point conversion, which remains at the 2-yard line, is the better bet for NFL teams to follow.

"What does this mean?" Urschel wrote. "Little to nothing! But, won’t extra points be significantly harder now that they’re so much farther back? Won’t this incentivize coaches to go for two? No, and no. Good data on field goal success rate is somewhat hard to come by, unless you’re looking at ranges of field goals. Lucky for me, a few guys from MIT already did the heavy-lifting for me."

Leaning on the data for extra points and two-point conversions, Urschel came up with the following formulas to predict the probability of converting each one:

"It doesn’t take a probability theorist to know that the expected points (the sum of each possible point outcome times the likelihood of each occurring) of the two-point conversion is now higher than that of an extra point kick," Urschel wrote. "E(two-point conversion) = 2x.479 + 0x(1-.479) = .958 points E(extra point) = 1x.928 + 0x(1-.928) = .928 points

"It’s simple math, right? The expected points for two-point conversions is greater, so of course all 32 NFL teams are going to do away with extra points and go for two every time, right? Not so fast. Just because the expected points of one endeavor is greater than the other, doesn’t mean it is what coaches are going to do."

In Urschel's opinion, NFL coaches will remain fairly conservative in their philosophy and will still avoid going for two points despite the increased length of extra points.

"Because, as you might have surmised at some point, NFL coaches are risk averse," Urschel wrote. "Coaches like low variation, and a difference of .03 expected points per extra point is not nearly enough to deter them from the safer choice of going with a slightly longer kick (which has variance of .07) as opposed to the much riskier two-point conversion (which has variance .25). There may be some who embrace the new system and take advantage of this opportunity, but my guess is most won’t."

awilson@baltsun.com

twitter.com/RavensInsider